sorry if they are not very practical for C # Asp.Net, I hope to make me understand
I have this situation
string content = ClearHTMLTags(HttpUtility.HtmlDecode(e.Body));
((Post)sender).Description = content + "...";
You can remove all whitespaces with this regex
content = Regex.Replace(content, @"\s+", string.Empty);
what are whitespace characters from MSDN.
Btw you are mistaking
Trim with removing spaces, in fact it's only removing spaces at the begining and at the end of string. If you want to replace all spaces and carige returns use my regex.